1. Field of the Invention
The present invention relates to a technique to transmit audio information and image information, and more particularly to an audio and image information transmitting device that transmits sound recorded in a telephone device and image from a doorphone system by e-mail.
2. Discussion of the Background
A telephone device and a doorphone system are typically used as communication means as home appliances. The telephone device, which is widely used in order that an user inside the building may communicate with the other party, may have an additional function such as a recording function that automatically records a message of a caller when the user is not available as well as a typical function of direct communication between the user and the other party. Due to the additional recording function, the user may listen the message of the caller later when he/she gets back.
A user who is inside a building may identify a visitor through the doorphone system which includes a CCD camera for picking up an image of the visitor and a display means for displaying the image thereon.
FIG. 1 illustrates a conventional telephone device provided with an answering machine 100 which is connected with telephone lines L1 and L2.
As shown therein, the telephone device having the answering machine 100 is comprised of a microprocessor 101, a speech network unit 102, a tone ringer 103 and a recording/playback unit 104. The microprocessor 101 controls the operation of each unit of the device 100. The speech network unit 102 is connected with a handset 105 and forms a communication network. The tone ringer 103 rings a bell by receiving a ring signal which is inputted over the telephone lines L1, L2 and outputs a ring signal to the lines L1, L2, when the user makes a call by operating a keypad 106. The recording/playback unit 104 outputs a message informing that the user is not able to answer the phone or stores the message of the caller in an internal unit thereof. The ring signals which are externally applied over the telephone lines L1, L2 are detected over a condenser C1 and a resistor R1.
Reference HS is a hook switch, BD1 is a first bridge diode connected between the hook switch HS and the speech network unit 102, and BD2 is a second bridge diode connected with the tone ringer 103.
When the user picks up the handset 105 to make a phone call, the microprocessor 101 controls the hook switch HS to connected with a terminal SWb. In such off-hook state, when the user selects a telephone number using the keypad 106, the microprocessor 101 converts the inputted telephone number to a predetermined signal, and the signal passing through the speech network unit 103 and the first bridge diode BD1 is transmitted to the other party over the telephone lines L1, L2.
On the contrary, in an on-hook state which the hook switch HS is connected with a terminal SWa, when the user receives the phone call from the other party, the ring signal detected across the condenser C1 and the resistor R1 is transmitted to the tone ringer 103 over the second bridge diode BD2, thus the bell rings at the tone ringer 103.
The microprocessor 101 counts the number of the telephone rings.
When the user picks up the handset 105 before the predetermined number of times of the bell rings, the microprocessor 101 switches the state of the hook switch HS into the off-hook state, the communication network is formed by the speech network unit 102 so that the user can communicate with the caller, designating a telephone mode.
Meanwhile, if the user does not pick up the phone until the predetermined times of the bell ring, the recording/playback unit 104 operates under the control of the microprocessor 101 and outputs a message that the user is not available which designates a recording mode. The outputted message is transmitted to the caller over the telephone lines L1, L2 and an audio signal which corresponds to the message of the caller is recorded in the recording/playback unit 104 over the first bridge diode BD1 and the speech network unit 102. When the recording is finished, the hook switch HS is connected with the terminal SWb, driven by the microprocessor 101. In addition, the microprocessor 101 suspends the operation of the recording/playback unit 104, thereby completing the recording process.
When the user presses down the playback keys on the keypad 106, the recording/playback unit 104 is switched to the playback mode in accordance with the control of the microprocessor 101 so that the user may listen the message recorded in the answering machine.
However, according to the conventional telephone device having the answering machine, the recorded message is played back by which the user presses down the playback key. That is, since the telephone device is designed to be operated under the handling of the user, in order to listen the recorded message the user must manually operate the answering machine. To solve such a problem, the microprocessor 101 has an additional function to transmit the message recorded in the recording/playback unit 104 to the user when he/she calls and inputs an ID number from the outside. However, if the user receives the recorded message from a longdistance area or overseas, the user has to pay a great deal of telephone charges.
FIG. 2 illustrates a conventional doorphone system 300 in block diagram form.
As shown therein, the doorphone system 300 which enables an user inside the building to identify visitors is comprised of an external device 300A which is located out of the building and an internal device 300B installed in the building. The external device 300A is provided with a bell switch 301, a first microphone 302, a first speaker 306 and a CCD camera 307, and the internal device 300B is provided with a bell 309, a second speaker 312, a second microphone 313 and a liquid crystal display (LCD) 318.
When a visitor presses the bell switch 301, the bell signal is generated, converted in the bell 309 and transmitted to the second speaker 312 over a mixer 311 so that the user inside the building may hear the bell sound. The CCD camera 307 starts to operate when the bell switch 301 is pressed, picks up the image of the visitor and outputs a predetermined image signal corresponding to the image thereof. The image signal passing through a second output buffer 308 and an input buffer 316 is processed in an image processing unit 317 and the processed image is displayed in the LCD 318.
The first and second microphones 302, 313 and the first and second speakers 306, 312 are used for the communication between the user and the visitor. The voice of the visitor is transmitted to the user over the first microphone 302, a first amp 303, a first output buffer 304, a second amp 310, the mixer 311 and the second speaker 312, while the voice of the user is transmitted to the visitor side over the second microphone 313, a fourth amp 313, a third output buffer 315, a third amp 305 and the first speaker 306.
However, the conventional doorphone system also has a problem similar to the problem that the above-described telephone device having the answering machine has. That is, since the doorphone system must be manually operated by the user, the user can not identify the visitor from the remote distance.